This invention relates to the control of motor vehicle accessories, particularly those, such as power door locks, windows sun roofs, hidden headlight activators or the like, which include a DC electric motor activatable reversibly through a relay controlled H-switch arrangement. Such a control may also include a control module having a module logic circuit providing automatic control of the accessory in response to sensed vehicle actions or conditions; and the module requires input and output terminals connected by wires in the vehicle wiring harness to input signal generating devices, motor control relays and the source of electric power. The latter connections are generally made to B+ and ground busses in the vehicle wiring harness through two module power terminals.